tracking billfish in panama: inside the guy harvey foundation’s research expedition

The Guy Harvey Foundation partners with Stanford University, the Harte Research Institute at Texas A&M University, and Tropic Star Lodge to study the movements and life history of billfish in the Eastern Tropical Pacific Ocean. This is one of the most highly productive regions of the ocean and understanding where these animals migrate is fundamental to ensuring sustainable management of these ecologically and economically important species.

The Eastern Tropical Pacific is one of the most highly productive regions of the ocean and understanding where these animals migrate is fundamental to ensuring sustainable management.

Billfish Research in Panama's Eastern Tropical Pacific

Jessica excitedly welcomed three scientists from the Harte Research Institute, Corpus Christi, in Panama City for their first collaborative effort to support Eastern Tropical Pacific studies already taking place in the region. After a night in Panama City, the group was collected from the hotel early the next day to head to Tropic Star Lodge on a 12-passenger Caravan, followed by a tractor trailer, affectionately known as the “Green Marlin” or “Jungle Limo,” before jumping into a panga to be taken to the lodge itself. Located on the edge of the Darien Jungle, one of the most biodiverse stretches of rainforest still intact, its magnificence can’t easily be described but rather felt; a sacred, lush, green mountainous place where you expect a pterodactyl to fly around the corner any second.

How Scientists Track Marlin and Sailfish

The goal was for the team to pilot data collection using acoustic receivers and complement it with pop-off archival satellite tags and dart, or “spaghetti,” tags on certain inshore and offshore species. With help from Tropic Star Lodge’s (TSL) mates, captains and logistics team, the first seven receivers were successfully deployed. Now, any animal with an acoustic transmitter, attached using a dart pole, could theoretically be picked up within 1,000m of the receiver itself. Dr. Alexandra Prouse, Dr. Matthew Streich and Dr. Kesley Banks each took turns tagging blue marlin and sailfish, while Jessica and Keishmer Hermoso, TSL’s own videographer, assisted by documenting the process.

Understanding Acoustic, Satellite, and Dart Tags

All avid anglers themselves, each took turns fighting the fish too, being careful to quickly and calmly bring it to the boat while another team member took care of the tagging and a third handled the data collection. Acoustic transmitters can last as long as five years, with the data downloaded from the receiver itself. Pop-off satellite tags will last for a programmed length of time, archive the data and then send it to researchers via satellite. Dart tags, in comparison, use a mark-recapture method that gives each tagged fish a unique number to be identified by other anglers if recaught — and can be deployed by any angler! All that’s needed is the tagging pole, a data record and a picture of the effort, if possible. The angler and/or TSL logistics team would then send it to the HRI team to add to the database. If the fish is recaptured, the data from the original deployment to its next capture can then be compared.

How Anglers Can Contribute to Billfish Conservation

During the fishing tutorial, Dr. Streich gave an overview of how guests could participate in the citizen science effort, and the participation was noteworthy. Guests were proud to be able to contribute something to the greater good of science while still enjoying the fish encounters they flew there to experience. As the data is so valuable, rewards are made available to incentivize people who come across tags to report them and, if possible, return the electronic tags so they can be reused and all available data downloaded.

20 Sailfish Tagged and More Marine Discoveries

Along with 20 sailfish being tagged, the team got to experience their first roosterfish catch and release, see humpback whales breaching and witness rare seabirds like the Inca Tern (seriously, you’ll want to see what this looks like) making an effort to catch fish next to waves crashing against large volcanic boulders. Several dolphinfish were also tagged, and data was collected from other species to support existing work by the Dolphinfish Research Program and Stanford team. After returning from the fishing day, we transformed from performance wear, sunblock and Xtratuf boots to dinner attire that was both sophisticated and versatile enough for a game of around-the-world ping pong and a bit of friendly competition and banter with guests."

Black Marlin Tagging: The Expedition Continues

The second part of the expedition began with a half day on the water. We left at 11 a.m. aboard “Spain” with Jesus, Manuel and Keishmer, stopping at the reef for bait, where rough-toothed dolphins helped themselves to some of it. From there, we trolled live bait out to La Tetas on the shelf edge and soon had a doubleheader: an 80-pound yellowfin tuna and a seven-foot silky shark. At 12:20, Candelo hooked a black marlin on the reef, but we couldn’t run in for the transfer because we were busy with the doubleheader. We also missed two sailfish that afternoon.

The following day, we headed back out on “Spain” with Jessica and Keishmer, collected bait and were live-bait fishing by 7:15 a.m. At 7:55, Capt. Fidel aboard “Future Minds” called to let us know they had hooked a black marlin, with Brian Austin on the rod. We ran over in time to catch some jumps from the 300-pound fish before transferring it to our boat, with Jessica taking over on the rod. After more jumps, we were able to get the leader, but the fish was still fresh and Manuel had to dump it twice. “Future Minds” stayed close by to watch the tagging process. We tagged the marlin after 45 minutes, and Jessica jumped in to film it, but it had already swum away very quickly in a perfect release.

Tagging 600-Pound and 400-Pound Black Marlin

Day three was a perfect day. Dr. Chloe Mikles from Stanford University arrived and met us offshore on a flat-calm sea, and our luck changed immediately. We released a sailfish that Jessica and Keishmer filmed at the boat, and as we moved along at two knots, I put out a big black-and-purple lure about 50 feet behind us. Ten seconds later, a 600-pound black marlin crashed it and went dumping away toward the horizon. I managed to get some great shots as Jessica fought the fish on 80-pound line. It took a solid 90 minutes to get it to the boat for tagging, and afterward we were able to swim with it for a while.

Running back into the reef to get more bait, we immediately raised another black marlin. Chloe fought it for 20 minutes before we tagged the approximately 400-pound fish, giving us even more great action shots. It was amazing to have two big marlins only an hour apart during “low season.”

Continuing Research for Billfish Conservation

There wasn’t much luck over the next three days, with mostly sailfish and sharks making appearances. Jessica and I headed home while Chloe remained, continuing the tagging work aboard Spain with Ermel and Luis, along with eager help from the TSL staff. She was able to deploy three more tags on black marlin while there, so thanks again to the amazing TSL crews and their superb staff, we had another incredible expedition.

Keishmer Hermoso expertly filmed all the tagging and other action, providing footage used for GHF’s educational content. The bonus is always having Jessica accompany me on these exciting expeditions, as she is energetic, capable and a wonderful diver who captures awesome images.